iirs: reduce size of signal_declaration.

16 files changed, 317 insertions, 236 deletions

diff --git a/src/vhdl/canon.adb b/src/vhdl/canon.adb
index 883e89e1b..8b8ffe49a 100644
--- a/src/vhdl/canon.adb
+++ b/src/vhdl/canon.adb
@@ -2172,7 +2172,7 @@ package body Canon is
       while El /= Null_Iir loop
          if Get_Kind (El) = Iir_Kind_Signal_Declaration
            and then Get_Type (El) = Dis_Type
-           and then Get_Signal_Kind (El) /= Iir_No_Signal_Kind
+           and then Get_Guarded_Signal_Flag (El)
          then
             if not Get_Has_Disconnect_Flag (El) then
                Set_Has_Disconnect_Flag (El, True);
diff --git a/src/vhdl/disp_tree.adb b/src/vhdl/disp_tree.adb
index fbaaa939b..1fd3bd500 100644
--- a/src/vhdl/disp_tree.adb
+++ b/src/vhdl/disp_tree.adb
@@ -226,8 +226,6 @@ package body Disp_Tree is
    function Image_Iir_Signal_Kind (Kind : Iir_Signal_Kind) return String is
    begin
       case Kind is
-         when Iir_No_Signal_Kind =>
-            return "no";
          when Iir_Register_Kind =>
             return "register";
          when Iir_Bus_Kind =>
diff --git a/src/vhdl/disp_vhdl.adb b/src/vhdl/disp_vhdl.adb
index 3683ae5e3..f67261862 100644
--- a/src/vhdl/disp_vhdl.adb
+++ b/src/vhdl/disp_vhdl.adb
@@ -1009,16 +1009,16 @@ package body Disp_Vhdl is
       end case;
    end Disp_Mode;
 
-   procedure Disp_Signal_Kind (Kind: Iir_Signal_Kind) is
-   begin
-      case Kind is
-         when Iir_No_Signal_Kind =>
-            null;
-         when Iir_Register_Kind =>
-            Put (" register");
-         when Iir_Bus_Kind =>
-            Put (" bus");
-      end case;
+   procedure Disp_Signal_Kind (Sig : Iir) is
+   begin
+      if Get_Guarded_Signal_Flag (Sig) then
+         case Get_Signal_Kind (Sig) is
+            when Iir_Register_Kind =>
+               Put (" register");
+            when Iir_Bus_Kind =>
+               Put (" bus");
+         end case;
+      end if;
    end Disp_Signal_Kind;
 
    procedure Disp_Interface_Class (Inter: Iir) is
@@ -1055,7 +1055,7 @@ package body Disp_Vhdl is
          Disp_Subtype_Indication (Get_Subtype_Indication (Inter));
       end if;
       if Get_Kind (Inter) = Iir_Kind_Interface_Signal_Declaration then
-         Disp_Signal_Kind (Get_Signal_Kind (Inter));
+         Disp_Signal_Kind (Inter);
       end if;
       if Default /= Null_Iir then
          Put (" := ");
@@ -1396,7 +1396,7 @@ package body Disp_Vhdl is
       Put (": ");
       Disp_Subtype_Indication (Get_Subtype_Indication (Decl));
       if Get_Kind (Decl) = Iir_Kind_Signal_Declaration then
-         Disp_Signal_Kind (Get_Signal_Kind (Decl));
+         Disp_Signal_Kind (Decl);
       end if;
 
       if Get_Default_Value (Decl) /= Null_Iir then
diff --git a/src/vhdl/ieee-vital_timing.adb b/src/vhdl/ieee-vital_timing.adb
index d7166da5d..3b94e3e0b 100644
--- a/src/vhdl/ieee-vital_timing.adb
+++ b/src/vhdl/ieee-vital_timing.adb
@@ -294,7 +294,7 @@ package body Ieee.Vital_Timing is
                       Decl);
       end if;
 
-      if Get_Signal_Kind (Decl) /= Iir_No_Signal_Kind then
+      if Get_Guarded_Signal_Flag (Decl) then
          Error_Vital ("VITAL entity port cannot be guarded", Decl);
       end if;
    end Check_Entity_Port_Declaration;
diff --git a/src/vhdl/iirs.adb b/src/vhdl/iirs.adb
index 92bd7a122..43d7658bb 100644
--- a/src/vhdl/iirs.adb
+++ b/src/vhdl/iirs.adb
@@ -208,6 +208,11 @@ package body Iirs is
    function Iir_Delay_Mechanism_To_Boolean is new Ada.Unchecked_Conversion
      (Source => Iir_Delay_Mechanism, Target => Boolean);
 
+   function Boolean_To_Iir_Signal_Kind is new Ada.Unchecked_Conversion
+     (Source => Boolean, Target => Iir_Signal_Kind);
+   function Iir_Signal_Kind_To_Boolean is new Ada.Unchecked_Conversion
+     (Source => Iir_Signal_Kind, Target => Boolean);
+
    function Iir_To_String_Id is new Ada.Unchecked_Conversion
      (Source => Iir, Target => String_Id);
    function String_Id_To_Iir is new Ada.Unchecked_Conversion
@@ -299,6 +304,7 @@ package body Iirs is
            | Iir_Kind_Terminal_Declaration
            | Iir_Kind_Free_Quantity_Declaration
            | Iir_Kind_Object_Alias_Declaration
+           | Iir_Kind_Signal_Declaration
            | Iir_Kind_Variable_Declaration
            | Iir_Kind_Identity_Operator
            | Iir_Kind_Negation_Operator
@@ -452,7 +458,6 @@ package body Iirs is
            | Iir_Kind_Procedure_Body
            | Iir_Kind_File_Declaration
            | Iir_Kind_Guard_Signal_Declaration
-           | Iir_Kind_Signal_Declaration
            | Iir_Kind_Constant_Declaration
            | Iir_Kind_Iterator_Declaration
            | Iir_Kind_Interface_Constant_Declaration
@@ -1655,18 +1660,32 @@ package body Iirs is
       Set_Odigit1 (Target, Iir_Mode'Pos (Mode));
    end Set_Mode;
 
+   function Get_Guarded_Signal_Flag (Target : Iir) return Boolean is
+   begin
+      pragma Assert (Target /= Null_Iir);
+      pragma Assert (Has_Guarded_Signal_Flag (Get_Kind (Target)));
+      return Get_Flag8 (Target);
+   end Get_Guarded_Signal_Flag;
+
+   procedure Set_Guarded_Signal_Flag (Target : Iir; Guarded : Boolean) is
+   begin
+      pragma Assert (Target /= Null_Iir);
+      pragma Assert (Has_Guarded_Signal_Flag (Get_Kind (Target)));
+      Set_Flag8 (Target, Guarded);
+   end Set_Guarded_Signal_Flag;
+
    function Get_Signal_Kind (Target : Iir) return Iir_Signal_Kind is
    begin
       pragma Assert (Target /= Null_Iir);
       pragma Assert (Has_Signal_Kind (Get_Kind (Target)));
-      return Iir_Signal_Kind'Val (Get_State3 (Target));
+      return Boolean_To_Iir_Signal_Kind (Get_Flag9 (Target));
    end Get_Signal_Kind;
 
    procedure Set_Signal_Kind (Target : Iir; Signal_Kind : Iir_Signal_Kind) is
    begin
       pragma Assert (Target /= Null_Iir);
       pragma Assert (Has_Signal_Kind (Get_Kind (Target)));
-      Set_State3 (Target, Iir_Signal_Kind'Pos (Signal_Kind));
+      Set_Flag9 (Target, Iir_Signal_Kind_To_Boolean (Signal_Kind));
    end Set_Signal_Kind;
 
    function Get_Base_Name (Target : Iir) return Iir is
diff --git a/src/vhdl/iirs.adb.in b/src/vhdl/iirs.adb.in
index b44eb4f0c..d8e8bc0e4 100644
--- a/src/vhdl/iirs.adb.in
+++ b/src/vhdl/iirs.adb.in
@@ -208,6 +208,11 @@ package body Iirs is
    function Iir_Delay_Mechanism_To_Boolean is new Ada.Unchecked_Conversion
      (Source => Iir_Delay_Mechanism, Target => Boolean);
 
+   function Boolean_To_Iir_Signal_Kind is new Ada.Unchecked_Conversion
+     (Source => Boolean, Target => Iir_Signal_Kind);
+   function Iir_Signal_Kind_To_Boolean is new Ada.Unchecked_Conversion
+     (Source => Iir_Signal_Kind, Target => Boolean);
+
    function Iir_To_String_Id is new Ada.Unchecked_Conversion
      (Source => Iir, Target => String_Id);
    function String_Id_To_Iir is new Ada.Unchecked_Conversion
diff --git a/src/vhdl/iirs.ads b/src/vhdl/iirs.ads
index 591da44f1..00daef21e 100644
--- a/src/vhdl/iirs.ads
+++ b/src/vhdl/iirs.ads
@@ -1114,12 +1114,14 @@ package Iirs is
    --
    --   Get/Set_Is_Ref (Flag7)
    --
+   --   Get/Set_Guarded_Signal_Flag (Flag8)
+   --
+   -- Only for Iir_Kind_Interface_Signal_Declaration:
+   --   Get/Set_Signal_Kind (Flag9)
+   --
    --   Get/Set_Expr_Staticness (State1)
    --
    --   Get/Set_Name_Staticness (State2)
-   --
-   -- Only for Iir_Kind_Interface_Signal_Declaration:
-   --   Get/Set_Signal_Kind (State3)
 
    -- Iir_Kind_Interface_Package_Declaration (Medium)
    --
@@ -1324,7 +1326,7 @@ package Iirs is
    --
    --   Get/Set_Use_Flag (Flag6)
 
-   -- Iir_Kind_Signal_Declaration (Medium)
+   -- Iir_Kind_Signal_Declaration (Short)
    --
    --   Get/Set_Parent (Field0)
    --
@@ -1342,14 +1344,14 @@ package Iirs is
    --  a process/concurrent_statement for which the signal should have a
    --  driver.  This is used to catch at analyse time unresolved signals with
    --  several drivers.
-   --   Get/Set_Signal_Driver (Field7)
+   --  -- Get/Set_Signal_Driver (Field7)
    --
    --   Get/Set_Has_Disconnect_Flag (Flag1)
    --
-   --   Get/Set_Has_Identifier_List (Flag3)
-   --
    --   Get/Set_Has_Active_Flag (Flag2)
    --
+   --   Get/Set_Has_Identifier_List (Flag3)
+   --
    --   Get/Set_Visible_Flag (Flag4)
    --
    --   Get/Set_After_Drivers_Flag (Flag5)
@@ -1358,11 +1360,13 @@ package Iirs is
    --
    --   Get/Set_Is_Ref (Flag7)
    --
+   --   Get/Set_Guarded_Signal_Flag (Flag8)
+   --
+   --   Get/Set_Signal_Kind (Flag9)
+   --
    --   Get/Set_Expr_Staticness (State1)
    --
    --   Get/Set_Name_Staticness (State2)
-   --
-   --   Get/Set_Signal_Kind (State3)
 
    -- Iir_Kind_Guard_Signal_Declaration (Medium)
    --
@@ -1384,11 +1388,13 @@ package Iirs is
    --
    --   Get/Set_Use_Flag (Flag6)
    --
+   --   Get/Set_Guarded_Signal_Flag (Flag8)
+   --
+   --   Get/Set_Signal_Kind (Flag9)
+   --
    --   Get/Set_Expr_Staticness (State1)
    --
    --   Get/Set_Name_Staticness (State2)
-   --
-   --   Get/Set_Signal_Kind (State3)
 
    -- Iir_Kind_Constant_Declaration (Medium)
    -- Iir_Kind_Iterator_Declaration (Medium)
@@ -3649,10 +3655,9 @@ package Iirs is
 
    type Iir_Signal_Kind is
       (
-       Iir_No_Signal_Kind,
        Iir_Register_Kind,
        Iir_Bus_Kind
-       );
+      );
 
    --  If the order of elements in IIR_MODE is modified, also modify the
    --  order in GRT (types and rtis).
@@ -5332,7 +5337,12 @@ package Iirs is
    function Get_Mode (Target : Iir) return Iir_Mode;
    procedure Set_Mode (Target : Iir; Mode : Iir_Mode);
 
-   --  Field: State3 (pos)
+   --  True if the signal is guarded (has a signal kind).
+   --  Field: Flag8
+   function Get_Guarded_Signal_Flag (Target : Iir) return Boolean;
+   procedure Set_Guarded_Signal_Flag (Target : Iir; Guarded : Boolean);
+
+   --  Field: Flag9 (uc)
    function Get_Signal_Kind (Target : Iir) return Iir_Signal_Kind;
    procedure Set_Signal_Kind (Target : Iir; Signal_Kind : Iir_Signal_Kind);
 
diff --git a/src/vhdl/nodes.ads b/src/vhdl/nodes.ads
index adf6a5ee8..6b80703ed 100644
--- a/src/vhdl/nodes.ads
+++ b/src/vhdl/nodes.ads
@@ -39,20 +39,13 @@ package Nodes is
       Format_Int
      );
 
-   --  Future layout:    (rem)
-   --   Format: 0 bits    32
-   --   Nkind: 16 bits    16
-   --   Flags: 8*1 bits    8
-   --   State: 2*2 bits    4
-   --   Odigit is to be removed.
-
-   --  Future layout (2):(rem)
+   --  Current layout:    (rem)
    --   Format: 2 bits    30
-   --   Nkind:  8 bits    22 (vhdl: 216 nodes)
-   --   Flags: 8*1 bits   14
-   --   State: 2*2 bits   10
-   --   Lang:   2 bits     8
-   --   Odigit: 1*3 bits   5
+   --   Flags: 6*1 bits   24
+   --   Nkind:  8 bits    16 (vhdl: 216 nodes)
+   --   State: 2*2 bits   12
+   --   Flags: 6*1 bits    6
+   --   Odigit: 2*3 bits   0
 
    -- Common fields are:
    --   Flag1 : Boolean
diff --git a/src/vhdl/nodes_meta.adb b/src/vhdl/nodes_meta.adb
index 7e3aba364..f43c07743 100644
--- a/src/vhdl/nodes_meta.adb
+++ b/src/vhdl/nodes_meta.adb
@@ -102,6 +102,7 @@ package body Nodes_Meta is
       Field_Subtype_Definition => Type_Iir,
       Field_Nature => Type_Iir,
       Field_Mode => Type_Iir_Mode,
+      Field_Guarded_Signal_Flag => Type_Boolean,
       Field_Signal_Kind => Type_Iir_Signal_Kind,
       Field_Base_Name => Type_Iir,
       Field_Interface_Declaration_Chain => Type_Iir,
@@ -481,6 +482,8 @@ package body Nodes_Meta is
             return "nature";
          when Field_Mode =>
             return "mode";
+         when Field_Guarded_Signal_Flag =>
+            return "guarded_signal_flag";
          when Field_Signal_Kind =>
             return "signal_kind";
          when Field_Base_Name =>
@@ -1545,6 +1548,8 @@ package body Nodes_Meta is
             return Attr_None;
          when Field_Mode =>
             return Attr_None;
+         when Field_Guarded_Signal_Flag =>
+            return Attr_None;
          when Field_Signal_Kind =>
             return Attr_None;
          when Field_Base_Name =>
@@ -2794,9 +2799,10 @@ package body Nodes_Meta is
       Field_Has_Active_Flag,
       Field_Visible_Flag,
       Field_Use_Flag,
+      Field_Guarded_Signal_Flag,
+      Field_Signal_Kind,
       Field_Expr_Staticness,
       Field_Name_Staticness,
-      Field_Signal_Kind,
       Field_Guard_Expression,
       Field_Guard_Sensitivity_List,
       Field_Block_Statement,
@@ -2811,11 +2817,11 @@ package body Nodes_Meta is
       Field_After_Drivers_Flag,
       Field_Use_Flag,
       Field_Is_Ref,
+      Field_Guarded_Signal_Flag,
+      Field_Signal_Kind,
       Field_Expr_Staticness,
       Field_Name_Staticness,
-      Field_Signal_Kind,
       Field_Chain,
-      Field_Signal_Driver,
       Field_Default_Value,
       Field_Subtype_Indication,
       Field_Parent,
@@ -2868,6 +2874,7 @@ package body Nodes_Meta is
       Field_After_Drivers_Flag,
       Field_Use_Flag,
       Field_Is_Ref,
+      Field_Guarded_Signal_Flag,
       Field_Mode,
       Field_Lexical_Layout,
       Field_Expr_Staticness,
@@ -2883,6 +2890,7 @@ package body Nodes_Meta is
       Field_After_Drivers_Flag,
       Field_Use_Flag,
       Field_Is_Ref,
+      Field_Guarded_Signal_Flag,
       Field_Mode,
       Field_Lexical_Layout,
       Field_Expr_Staticness,
@@ -2901,11 +2909,12 @@ package body Nodes_Meta is
       Field_After_Drivers_Flag,
       Field_Use_Flag,
       Field_Is_Ref,
+      Field_Guarded_Signal_Flag,
+      Field_Signal_Kind,
       Field_Mode,
       Field_Lexical_Layout,
       Field_Expr_Staticness,
       Field_Name_Staticness,
-      Field_Signal_Kind,
       Field_Chain,
       Field_Default_Value,
       Field_Subtype_Indication,
@@ -2917,6 +2926,7 @@ package body Nodes_Meta is
       Field_After_Drivers_Flag,
       Field_Use_Flag,
       Field_Is_Ref,
+      Field_Guarded_Signal_Flag,
       Field_Mode,
       Field_Lexical_Layout,
       Field_Expr_Staticness,
@@ -3926,145 +3936,145 @@ package body Nodes_Meta is
       Iir_Kind_Procedure_Body => 704,
       Iir_Kind_Object_Alias_Declaration => 716,
       Iir_Kind_File_Declaration => 731,
-      Iir_Kind_Guard_Signal_Declaration => 743,
-      Iir_Kind_Signal_Declaration => 760,
-      Iir_Kind_Variable_Declaration => 773,
-      Iir_Kind_Constant_Declaration => 787,
-      Iir_Kind_Iterator_Declaration => 799,
-      Iir_Kind_Interface_Constant_Declaration => 813,
-      Iir_Kind_Interface_Variable_Declaration => 827,
-      Iir_Kind_Interface_Signal_Declaration => 845,
-      Iir_Kind_Interface_File_Declaration => 859,
-      Iir_Kind_Interface_Package_Declaration => 868,
-      Iir_Kind_Identity_Operator => 872,
-      Iir_Kind_Negation_Operator => 876,
-      Iir_Kind_Absolute_Operator => 880,
-      Iir_Kind_Not_Operator => 884,
-      Iir_Kind_Condition_Operator => 888,
-      Iir_Kind_Reduction_And_Operator => 892,
-      Iir_Kind_Reduction_Or_Operator => 896,
-      Iir_Kind_Reduction_Nand_Operator => 900,
-      Iir_Kind_Reduction_Nor_Operator => 904,
-      Iir_Kind_Reduction_Xor_Operator => 908,
-      Iir_Kind_Reduction_Xnor_Operator => 912,
-      Iir_Kind_And_Operator => 917,
-      Iir_Kind_Or_Operator => 922,
-      Iir_Kind_Nand_Operator => 927,
-      Iir_Kind_Nor_Operator => 932,
-      Iir_Kind_Xor_Operator => 937,
-      Iir_Kind_Xnor_Operator => 942,
-      Iir_Kind_Equality_Operator => 947,
-      Iir_Kind_Inequality_Operator => 952,
-      Iir_Kind_Less_Than_Operator => 957,
-      Iir_Kind_Less_Than_Or_Equal_Operator => 962,
-      Iir_Kind_Greater_Than_Operator => 967,
-      Iir_Kind_Greater_Than_Or_Equal_Operator => 972,
-      Iir_Kind_Match_Equality_Operator => 977,
-      Iir_Kind_Match_Inequality_Operator => 982,
-      Iir_Kind_Match_Less_Than_Operator => 987,
-      Iir_Kind_Match_Less_Than_Or_Equal_Operator => 992,
-      Iir_Kind_Match_Greater_Than_Operator => 997,
-      Iir_Kind_Match_Greater_Than_Or_Equal_Operator => 1002,
-      Iir_Kind_Sll_Operator => 1007,
-      Iir_Kind_Sla_Operator => 1012,
-      Iir_Kind_Srl_Operator => 1017,
-      Iir_Kind_Sra_Operator => 1022,
-      Iir_Kind_Rol_Operator => 1027,
-      Iir_Kind_Ror_Operator => 1032,
-      Iir_Kind_Addition_Operator => 1037,
-      Iir_Kind_Substraction_Operator => 1042,
-      Iir_Kind_Concatenation_Operator => 1047,
-      Iir_Kind_Multiplication_Operator => 1052,
-      Iir_Kind_Division_Operator => 1057,
-      Iir_Kind_Modulus_Operator => 1062,
-      Iir_Kind_Remainder_Operator => 1067,
-      Iir_Kind_Exponentiation_Operator => 1072,
-      Iir_Kind_Function_Call => 1080,
-      Iir_Kind_Aggregate => 1086,
-      Iir_Kind_Parenthesis_Expression => 1089,
-      Iir_Kind_Qualified_Expression => 1093,
-      Iir_Kind_Type_Conversion => 1098,
-      Iir_Kind_Allocator_By_Expression => 1102,
-      Iir_Kind_Allocator_By_Subtype => 1106,
-      Iir_Kind_Selected_Element => 1112,
-      Iir_Kind_Dereference => 1117,
-      Iir_Kind_Implicit_Dereference => 1122,
-      Iir_Kind_Slice_Name => 1129,
-      Iir_Kind_Indexed_Name => 1135,
-      Iir_Kind_Psl_Expression => 1137,
-      Iir_Kind_Sensitized_Process_Statement => 1156,
-      Iir_Kind_Process_Statement => 1174,
-      Iir_Kind_Concurrent_Conditional_Signal_Assignment => 1185,
-      Iir_Kind_Concurrent_Selected_Signal_Assignment => 1197,
-      Iir_Kind_Concurrent_Assertion_Statement => 1205,
-      Iir_Kind_Psl_Default_Clock => 1209,
-      Iir_Kind_Psl_Assert_Statement => 1218,
-      Iir_Kind_Psl_Cover_Statement => 1227,
-      Iir_Kind_Concurrent_Procedure_Call_Statement => 1233,
-      Iir_Kind_Block_Statement => 1246,
-      Iir_Kind_Generate_Statement => 1258,
-      Iir_Kind_Component_Instantiation_Statement => 1268,
-      Iir_Kind_Simple_Simultaneous_Statement => 1275,
-      Iir_Kind_Signal_Assignment_Statement => 1284,
-      Iir_Kind_Null_Statement => 1288,
-      Iir_Kind_Assertion_Statement => 1295,
-      Iir_Kind_Report_Statement => 1301,
-      Iir_Kind_Wait_Statement => 1308,
-      Iir_Kind_Variable_Assignment_Statement => 1314,
-      Iir_Kind_Return_Statement => 1320,
-      Iir_Kind_For_Loop_Statement => 1328,
-      Iir_Kind_While_Loop_Statement => 1335,
-      Iir_Kind_Next_Statement => 1341,
-      Iir_Kind_Exit_Statement => 1347,
-      Iir_Kind_Case_Statement => 1354,
-      Iir_Kind_Procedure_Call_Statement => 1359,
-      Iir_Kind_If_Statement => 1367,
-      Iir_Kind_Elsif => 1372,
-      Iir_Kind_Character_Literal => 1379,
-      Iir_Kind_Simple_Name => 1386,
-      Iir_Kind_Selected_Name => 1394,
-      Iir_Kind_Operator_Symbol => 1399,
-      Iir_Kind_Selected_By_All_Name => 1404,
-      Iir_Kind_Parenthesis_Name => 1408,
-      Iir_Kind_Base_Attribute => 1410,
-      Iir_Kind_Left_Type_Attribute => 1415,
-      Iir_Kind_Right_Type_Attribute => 1420,
-      Iir_Kind_High_Type_Attribute => 1425,
-      Iir_Kind_Low_Type_Attribute => 1430,
-      Iir_Kind_Ascending_Type_Attribute => 1435,
-      Iir_Kind_Image_Attribute => 1441,
-      Iir_Kind_Value_Attribute => 1447,
-      Iir_Kind_Pos_Attribute => 1453,
-      Iir_Kind_Val_Attribute => 1459,
-      Iir_Kind_Succ_Attribute => 1465,
-      Iir_Kind_Pred_Attribute => 1471,
-      Iir_Kind_Leftof_Attribute => 1477,
-      Iir_Kind_Rightof_Attribute => 1483,
-      Iir_Kind_Delayed_Attribute => 1491,
-      Iir_Kind_Stable_Attribute => 1499,
-      Iir_Kind_Quiet_Attribute => 1507,
-      Iir_Kind_Transaction_Attribute => 1515,
-      Iir_Kind_Event_Attribute => 1519,
-      Iir_Kind_Active_Attribute => 1523,
-      Iir_Kind_Last_Event_Attribute => 1527,
-      Iir_Kind_Last_Active_Attribute => 1531,
-      Iir_Kind_Last_Value_Attribute => 1535,
-      Iir_Kind_Driving_Attribute => 1539,
-      Iir_Kind_Driving_Value_Attribute => 1543,
-      Iir_Kind_Behavior_Attribute => 1543,
-      Iir_Kind_Structure_Attribute => 1543,
-      Iir_Kind_Simple_Name_Attribute => 1550,
-      Iir_Kind_Instance_Name_Attribute => 1555,
-      Iir_Kind_Path_Name_Attribute => 1560,
-      Iir_Kind_Left_Array_Attribute => 1567,
-      Iir_Kind_Right_Array_Attribute => 1574,
-      Iir_Kind_High_Array_Attribute => 1581,
-      Iir_Kind_Low_Array_Attribute => 1588,
-      Iir_Kind_Length_Array_Attribute => 1595,
-      Iir_Kind_Ascending_Array_Attribute => 1602,
-      Iir_Kind_Range_Array_Attribute => 1609,
-      Iir_Kind_Reverse_Range_Array_Attribute => 1616,
-      Iir_Kind_Attribute_Name => 1624
+      Iir_Kind_Guard_Signal_Declaration => 744,
+      Iir_Kind_Signal_Declaration => 761,
+      Iir_Kind_Variable_Declaration => 774,
+      Iir_Kind_Constant_Declaration => 788,
+      Iir_Kind_Iterator_Declaration => 800,
+      Iir_Kind_Interface_Constant_Declaration => 815,
+      Iir_Kind_Interface_Variable_Declaration => 830,
+      Iir_Kind_Interface_Signal_Declaration => 849,
+      Iir_Kind_Interface_File_Declaration => 864,
+      Iir_Kind_Interface_Package_Declaration => 873,
+      Iir_Kind_Identity_Operator => 877,
+      Iir_Kind_Negation_Operator => 881,
+      Iir_Kind_Absolute_Operator => 885,
+      Iir_Kind_Not_Operator => 889,
+      Iir_Kind_Condition_Operator => 893,
+      Iir_Kind_Reduction_And_Operator => 897,
+      Iir_Kind_Reduction_Or_Operator => 901,
+      Iir_Kind_Reduction_Nand_Operator => 905,
+      Iir_Kind_Reduction_Nor_Operator => 909,
+      Iir_Kind_Reduction_Xor_Operator => 913,
+      Iir_Kind_Reduction_Xnor_Operator => 917,
+      Iir_Kind_And_Operator => 922,
+      Iir_Kind_Or_Operator => 927,
+      Iir_Kind_Nand_Operator => 932,
+      Iir_Kind_Nor_Operator => 937,
+      Iir_Kind_Xor_Operator => 942,
+      Iir_Kind_Xnor_Operator => 947,
+      Iir_Kind_Equality_Operator => 952,
+      Iir_Kind_Inequality_Operator => 957,
+      Iir_Kind_Less_Than_Operator => 962,
+      Iir_Kind_Less_Than_Or_Equal_Operator => 967,
+      Iir_Kind_Greater_Than_Operator => 972,
+      Iir_Kind_Greater_Than_Or_Equal_Operator => 977,
+      Iir_Kind_Match_Equality_Operator => 982,
+      Iir_Kind_Match_Inequality_Operator => 987,
+      Iir_Kind_Match_Less_Than_Operator => 992,
+      Iir_Kind_Match_Less_Than_Or_Equal_Operator => 997,
+      Iir_Kind_Match_Greater_Than_Operator => 1002,
+      Iir_Kind_Match_Greater_Than_Or_Equal_Operator => 1007,
+      Iir_Kind_Sll_Operator => 1012,
+      Iir_Kind_Sla_Operator => 1017,
+      Iir_Kind_Srl_Operator => 1022,
+      Iir_Kind_Sra_Operator => 1027,
+      Iir_Kind_Rol_Operator => 1032,
+      Iir_Kind_Ror_Operator => 1037,
+      Iir_Kind_Addition_Operator => 1042,
+      Iir_Kind_Substraction_Operator => 1047,
+      Iir_Kind_Concatenation_Operator => 1052,
+      Iir_Kind_Multiplication_Operator => 1057,
+      Iir_Kind_Division_Operator => 1062,
+      Iir_Kind_Modulus_Operator => 1067,
+      Iir_Kind_Remainder_Operator => 1072,
+      Iir_Kind_Exponentiation_Operator => 1077,
+      Iir_Kind_Function_Call => 1085,
+      Iir_Kind_Aggregate => 1091,
+      Iir_Kind_Parenthesis_Expression => 1094,
+      Iir_Kind_Qualified_Expression => 1098,
+      Iir_Kind_Type_Conversion => 1103,
+      Iir_Kind_Allocator_By_Expression => 1107,
+      Iir_Kind_Allocator_By_Subtype => 1111,
+      Iir_Kind_Selected_Element => 1117,
+      Iir_Kind_Dereference => 1122,
+      Iir_Kind_Implicit_Dereference => 1127,
+      Iir_Kind_Slice_Name => 1134,
+      Iir_Kind_Indexed_Name => 1140,
+      Iir_Kind_Psl_Expression => 1142,
+      Iir_Kind_Sensitized_Process_Statement => 1161,
+      Iir_Kind_Process_Statement => 1179,
+      Iir_Kind_Concurrent_Conditional_Signal_Assignment => 1190,
+      Iir_Kind_Concurrent_Selected_Signal_Assignment => 1202,
+      Iir_Kind_Concurrent_Assertion_Statement => 1210,
+      Iir_Kind_Psl_Default_Clock => 1214,
+      Iir_Kind_Psl_Assert_Statement => 1223,
+      Iir_Kind_Psl_Cover_Statement => 1232,
+      Iir_Kind_Concurrent_Procedure_Call_Statement => 1238,
+      Iir_Kind_Block_Statement => 1251,
+      Iir_Kind_Generate_Statement => 1263,
+      Iir_Kind_Component_Instantiation_Statement => 1273,
+      Iir_Kind_Simple_Simultaneous_Statement => 1280,
+      Iir_Kind_Signal_Assignment_Statement => 1289,
+      Iir_Kind_Null_Statement => 1293,
+      Iir_Kind_Assertion_Statement => 1300,
+      Iir_Kind_Report_Statement => 1306,
+      Iir_Kind_Wait_Statement => 1313,
+      Iir_Kind_Variable_Assignment_Statement => 1319,
+      Iir_Kind_Return_Statement => 1325,
+      Iir_Kind_For_Loop_Statement => 1333,
+      Iir_Kind_While_Loop_Statement => 1340,
+      Iir_Kind_Next_Statement => 1346,
+      Iir_Kind_Exit_Statement => 1352,
+      Iir_Kind_Case_Statement => 1359,
+      Iir_Kind_Procedure_Call_Statement => 1364,
+      Iir_Kind_If_Statement => 1372,
+      Iir_Kind_Elsif => 1377,
+      Iir_Kind_Character_Literal => 1384,
+      Iir_Kind_Simple_Name => 1391,
+      Iir_Kind_Selected_Name => 1399,
+      Iir_Kind_Operator_Symbol => 1404,
+      Iir_Kind_Selected_By_All_Name => 1409,
+      Iir_Kind_Parenthesis_Name => 1413,
+      Iir_Kind_Base_Attribute => 1415,
+      Iir_Kind_Left_Type_Attribute => 1420,
+      Iir_Kind_Right_Type_Attribute => 1425,
+      Iir_Kind_High_Type_Attribute => 1430,
+      Iir_Kind_Low_Type_Attribute => 1435,
+      Iir_Kind_Ascending_Type_Attribute => 1440,
+      Iir_Kind_Image_Attribute => 1446,
+      Iir_Kind_Value_Attribute => 1452,
+      Iir_Kind_Pos_Attribute => 1458,
+      Iir_Kind_Val_Attribute => 1464,
+      Iir_Kind_Succ_Attribute => 1470,
+      Iir_Kind_Pred_Attribute => 1476,
+      Iir_Kind_Leftof_Attribute => 1482,
+      Iir_Kind_Rightof_Attribute => 1488,
+      Iir_Kind_Delayed_Attribute => 1496,
+      Iir_Kind_Stable_Attribute => 1504,
+      Iir_Kind_Quiet_Attribute => 1512,
+      Iir_Kind_Transaction_Attribute => 1520,
+      Iir_Kind_Event_Attribute => 1524,
+      Iir_Kind_Active_Attribute => 1528,
+      Iir_Kind_Last_Event_Attribute => 1532,
+      Iir_Kind_Last_Active_Attribute => 1536,
+      Iir_Kind_Last_Value_Attribute => 1540,
+      Iir_Kind_Driving_Attribute => 1544,
+      Iir_Kind_Driving_Value_Attribute => 1548,
+      Iir_Kind_Behavior_Attribute => 1548,
+      Iir_Kind_Structure_Attribute => 1548,
+      Iir_Kind_Simple_Name_Attribute => 1555,
+      Iir_Kind_Instance_Name_Attribute => 1560,
+      Iir_Kind_Path_Name_Attribute => 1565,
+      Iir_Kind_Left_Array_Attribute => 1572,
+      Iir_Kind_Right_Array_Attribute => 1579,
+      Iir_Kind_High_Array_Attribute => 1586,
+      Iir_Kind_Low_Array_Attribute => 1593,
+      Iir_Kind_Length_Array_Attribute => 1600,
+      Iir_Kind_Ascending_Array_Attribute => 1607,
+      Iir_Kind_Range_Array_Attribute => 1614,
+      Iir_Kind_Reverse_Range_Array_Attribute => 1621,
+      Iir_Kind_Attribute_Name => 1629
      );
 
    function Get_Fields (K : Iir_Kind) return Fields_Array
@@ -4124,6 +4134,8 @@ package body Nodes_Meta is
             return Get_Same_Alternative_Flag (N);
          when Field_Need_Body =>
             return Get_Need_Body (N);
+         when Field_Guarded_Signal_Flag =>
+            return Get_Guarded_Signal_Flag (N);
          when Field_Deferred_Declaration_Flag =>
             return Get_Deferred_Declaration_Flag (N);
          when Field_Shared_Flag =>
@@ -4216,6 +4228,8 @@ package body Nodes_Meta is
             Set_Same_Alternative_Flag (N, V);
          when Field_Need_Body =>
             Set_Need_Body (N, V);
+         when Field_Guarded_Signal_Flag =>
+            Set_Guarded_Signal_Flag (N, V);
          when Field_Deferred_Declaration_Flag =>
             Set_Deferred_Declaration_Flag (N, V);
          when Field_Shared_Flag =>
@@ -6696,6 +6710,21 @@ package body Nodes_Meta is
       end case;
    end Has_Mode;
 
+   function Has_Guarded_Signal_Flag (K : Iir_Kind) return Boolean is
+   begin
+      case K is
+         when Iir_Kind_Guard_Signal_Declaration
+           | Iir_Kind_Signal_Declaration
+           | Iir_Kind_Interface_Constant_Declaration
+           | Iir_Kind_Interface_Variable_Declaration
+           | Iir_Kind_Interface_Signal_Declaration
+           | Iir_Kind_Interface_File_Declaration =>
+            return True;
+         when others =>
+            return False;
+      end case;
+   end Has_Guarded_Signal_Flag;
+
    function Has_Signal_Kind (K : Iir_Kind) return Boolean is
    begin
       case K is
@@ -6948,8 +6977,9 @@ package body Nodes_Meta is
    end Has_Block_Statement;
 
    function Has_Signal_Driver (K : Iir_Kind) return Boolean is
+      pragma Unreferenced (K);
    begin
-      return K = Iir_Kind_Signal_Declaration;
+      return False;
    end Has_Signal_Driver;
 
    function Has_Declaration_Chain (K : Iir_Kind) return Boolean is
diff --git a/src/vhdl/nodes_meta.ads b/src/vhdl/nodes_meta.ads
index 2d1f5e1c0..4e312e7d1 100644
--- a/src/vhdl/nodes_meta.ads
+++ b/src/vhdl/nodes_meta.ads
@@ -142,6 +142,7 @@ package Nodes_Meta is
       Field_Subtype_Definition,
       Field_Nature,
       Field_Mode,
+      Field_Guarded_Signal_Flag,
       Field_Signal_Kind,
       Field_Base_Name,
       Field_Interface_Declaration_Chain,
@@ -610,6 +611,7 @@ package Nodes_Meta is
    function Has_Subtype_Definition (K : Iir_Kind) return Boolean;
    function Has_Nature (K : Iir_Kind) return Boolean;
    function Has_Mode (K : Iir_Kind) return Boolean;
+   function Has_Guarded_Signal_Flag (K : Iir_Kind) return Boolean;
    function Has_Signal_Kind (K : Iir_Kind) return Boolean;
    function Has_Base_Name (K : Iir_Kind) return Boolean;
    function Has_Interface_Declaration_Chain (K : Iir_Kind) return Boolean;
diff --git a/src/vhdl/parse.adb b/src/vhdl/parse.adb
index 98895f4a6..1b4b41021 100644
--- a/src/vhdl/parse.adb
+++ b/src/vhdl/parse.adb
@@ -247,20 +247,29 @@ package body Parse is
    --  precond : next token
    --  postcond: next token
    --
-   --  [ §4.3.1.2 ]
+   --  [ LRM 4.3.1.2 ]
    --  signal_kind ::= REGISTER | BUS
    --
    --  If there is no signal_kind, then no_signal_kind is returned.
-   function Parse_Signal_Kind return Iir_Signal_Kind is
+   procedure Parse_Signal_Kind
+     (Is_Guarded : out Boolean; Signal_Kind : out Iir_Signal_Kind) is
    begin
       if Current_Token = Tok_Bus then
+         --  Eat 'bus'
          Scan;
-         return Iir_Bus_Kind;
+
+         Is_Guarded := True;
+         Signal_Kind := Iir_Bus_Kind;
       elsif Current_Token = Tok_Register then
+         --  Eat 'register'
          Scan;
-         return Iir_Register_Kind;
+
+         Is_Guarded := True;
+         Signal_Kind := Iir_Register_Kind;
       else
-         return Iir_No_Signal_Kind;
+         Is_Guarded := False;
+         --  Avoid uninitialized variable.
+         Signal_Kind := Iir_Bus_Kind;
       end if;
    end Parse_Signal_Kind;
 
@@ -974,6 +983,7 @@ package body Parse is
       Is_Default : Boolean;
       Interface_Mode: Iir_Mode;
       Interface_Type: Iir;
+      Is_Guarded : Boolean;
       Signal_Kind: Iir_Signal_Kind;
       Default_Value: Iir;
       Lexical_Layout : Iir_Lexical_Layout_Type;
@@ -1153,9 +1163,10 @@ package body Parse is
 
       --  Signal kind (but only for signal).
       if Get_Kind (Inter) = Iir_Kind_Interface_Signal_Declaration then
-         Signal_Kind := Parse_Signal_Kind;
+         Parse_Signal_Kind (Is_Guarded, Signal_Kind);
       else
-         Signal_Kind := Iir_No_Signal_Kind;
+         Is_Guarded := False;
+         Signal_Kind := Iir_Register_Kind;
       end if;
 
       if Current_Token = Tok_Assign then
@@ -1190,6 +1201,7 @@ package body Parse is
             Set_Lexical_Layout (Inter, Lexical_Layout);
          end if;
          if Get_Kind (Inter) = Iir_Kind_Interface_Signal_Declaration then
+            Set_Guarded_Signal_Flag (Inter, Is_Guarded);
             Set_Signal_Kind (Inter, Signal_Kind);
          end if;
          Inter := Get_Chain (Inter);
@@ -2864,6 +2876,7 @@ package body Parse is
       Default_Value : Iir;
       Mode: Iir_Mode;
       Signal_Kind : Iir_Signal_Kind;
+      Is_Guarded : Boolean;
       Open_Kind : Iir;
       Logical_Name : Iir;
       Kind: Iir_Kind;
@@ -2927,7 +2940,7 @@ package body Parse is
       Object_Type := Parse_Subtype_Indication;
 
       if Kind = Iir_Kind_Signal_Declaration then
-         Signal_Kind := Parse_Signal_Kind;
+         Parse_Signal_Kind (Is_Guarded, Signal_Kind);
       end if;
 
       if Current_Token = Tok_Assign then
@@ -2999,6 +3012,7 @@ package body Parse is
                Set_File_Logical_Name (Object, Logical_Name);
                Set_Has_Mode (Object, Has_Mode);
             when Iir_Kind_Signal_Declaration =>
+               Set_Guarded_Signal_Flag (Object, Is_Guarded);
                Set_Signal_Kind (Object, Signal_Kind);
             when others =>
                null;
diff --git a/src/vhdl/sem_decls.adb b/src/vhdl/sem_decls.adb
index 3230bf0f8..d5036c18a 100644
--- a/src/vhdl/sem_decls.adb
+++ b/src/vhdl/sem_decls.adb
@@ -104,35 +104,35 @@ package body Sem_Decls is
          Set_Type (Inter, A_Type);
 
          if Get_Kind (Inter) = Iir_Kind_Interface_Signal_Declaration then
-            case Get_Signal_Kind (Inter) is
-               when Iir_No_Signal_Kind =>
-                  null;
-               when Iir_Bus_Kind =>
-                  --  FIXME: where this test came from ?
-                  --  FIXME: from 4.3.1.2 ?
-                  if False
-                    and
-                    (Get_Kind (A_Type) not in Iir_Kinds_Subtype_Definition
-                       or else Get_Resolution_Indication (A_Type) = Null_Iir)
-                  then
-                     Error_Msg_Sem
-                       (Disp_Node (A_Type) & " of guarded " & Disp_Node (Inter)
-                          & " is not resolved", Inter);
-                  end if;
+            if Get_Guarded_Signal_Flag (Inter) then
+               case Get_Signal_Kind (Inter) is
+                  when Iir_Bus_Kind =>
+                     --  LRM93 4.3.1.2
+                     --  It is also an error if a guarded signal of a scalar
+                     --  type is neither a resolved signal nor a subelement of
+                     --  a resolved signal.
+                     if not Get_Resolved_Flag (A_Type) then
+                        Error_Msg_Sem
+                          (Disp_Node (A_Type) & " of guarded "
+                             & Disp_Node (Inter) & " is not resolved", Inter);
+                     end if;
 
-                  --  LRM 2.1.1.2  Signal parameter
-                  --  It is an error if the declaration of a formal signal
-                  --  parameter includes the reserved word BUS.
-                  if Flags.Vhdl_Std >= Vhdl_93
-                    and then Interface_Kind in Parameter_Interface_List
-                  then
+                     --  LRM 2.1.1.2  Signal parameter
+                     --  It is an error if the declaration of a formal signal
+                     --  parameter includes the reserved word BUS.
+                     if Flags.Vhdl_Std >= Vhdl_93
+                       and then Interface_Kind in Parameter_Interface_List
+                     then
+                        Error_Msg_Sem
+                          ("signal parameter can't be of kind bus", Inter);
+                     end if;
+                  when Iir_Register_Kind =>
+                     --  LRM93 4.3.2 Interface declarations
+                     --  Grammar for interface_signal_declaration.
                      Error_Msg_Sem
-                       ("signal parameter can't be of kind bus", Inter);
-                  end if;
-               when Iir_Register_Kind =>
-                  Error_Msg_Sem
-                    ("interface signal can't be of kind register", Inter);
-            end case;
+                       ("interface signal can't be of kind register", Inter);
+               end case;
+            end if;
             Set_Type_Has_Signal (A_Type);
          end if;
 
@@ -1683,10 +1683,10 @@ package body Sem_Decls is
 
          when Iir_Kind_Signal_Declaration =>
             --  LRM93 4.3.1.2
-            --  It is also an error if a guarded signal of a
-            --  scalar type is neither a resolved signal nor a
-            --  subelement of a resolved signal.
-            if Get_Signal_Kind (Decl) /= Iir_No_Signal_Kind
+            --  It is also an error if a guarded signal of a scalar type is
+            --  neither a resolved signal nor a subelement of a resolved
+            --  signal.
+            if Get_Guarded_Signal_Flag (Decl)
               and then not Get_Resolved_Flag (Atype)
             then
                Error_Msg_Sem
diff --git a/src/vhdl/sem_specs.adb b/src/vhdl/sem_specs.adb
index 7a6c180c8..1746903c1 100644
--- a/src/vhdl/sem_specs.adb
+++ b/src/vhdl/sem_specs.adb
@@ -991,7 +991,7 @@ package body Sem_Specs is
                if Get_Name_Staticness (Sig) /= Locally then
                   Error_Msg_Sem ("signal name must be locally static", El);
                end if;
-               if Get_Signal_Kind (Prefix) = Iir_No_Signal_Kind then
+               if not Get_Guarded_Signal_Flag (Prefix) then
                   Error_Msg_Sem ("signal must be a guarded signal", El);
                end if;
                Set_Has_Disconnect_Flag (Prefix, True);
diff --git a/src/vhdl/sem_stmts.adb b/src/vhdl/sem_stmts.adb
index d14276892..7712bb99f 100644
--- a/src/vhdl/sem_stmts.adb
+++ b/src/vhdl/sem_stmts.adb
@@ -379,7 +379,7 @@ package body Sem_Stmts is
       then
          Guarded_Target := Unknown;
       else
-         if Get_Signal_Kind (Target_Prefix) /= Iir_No_Signal_Kind then
+         if Get_Guarded_Signal_Flag (Target_Prefix) then
             Guarded_Target := True;
          else
             Guarded_Target := False;
diff --git a/src/vhdl/translate/trans-rtis.adb b/src/vhdl/translate/trans-rtis.adb
index 0b804370a..9bdc7a96d 100644
--- a/src/vhdl/translate/trans-rtis.adb
+++ b/src/vhdl/translate/trans-rtis.adb
@@ -1832,9 +1832,15 @@ package body Trans.Rtis is
          end case;
          case Get_Kind (Decl) is
             when Iir_Kind_Signal_Declaration
-               | Iir_Kind_Interface_Signal_Declaration =>
-               Mode := Mode
-                 + 16 * Iir_Signal_Kind'Pos (Get_Signal_Kind (Decl));
+              | Iir_Kind_Interface_Signal_Declaration =>
+               if Get_Guarded_Signal_Flag (Decl) then
+                  case Get_Signal_Kind (Decl) is
+                     when Iir_Register_Kind =>
+                        Mode := Mode + 16;
+                     when Iir_Bus_Kind =>
+                        Mode := Mode + 32;
+                  end case;
+               end if;
             when others =>
                null;
          end case;
diff --git a/src/xtools/pnodes.py b/src/xtools/pnodes.py
index e00cf4d89..f62180208 100755
--- a/src/xtools/pnodes.py
+++ b/src/xtools/pnodes.py
@@ -696,9 +696,13 @@ elif args.action == 'meta_body':
                 print
             for f in funcs:
                 gen_has_func_spec(f.name, ' is')
-                print '   begin'
                 choices = [k for k in kinds if f.name in nodes[k].attrs]
-                if len(choices) == 1:
+                if len(choices) == 0:
+                    print '      pragma Unreferenced (K);'
+                print '   begin'
+                if len(choices) == 0:
+                    print '      return False;'
+                elif len(choices) == 1:
                     print '      return K = ' + prefix_name + choices[0] + ';'
                 else:
                     print '      case K is'